Not sure. Where'd you find it in the car? Does it have a part number on it? If so, it can be identified at a parts counter or on a MINI parts website...
What everyone else said. Just be glad it's not an atual Mini/BMW part left there by mistake by a mechanic at the dealership. Happened to me. Had to drive back to see why they left it off only to find out it was a part for a 5 series. That resulted in an embarrassing (for the dealer) conversations why another car's parts were in my car.
As a matter of fact, my glove box latch doesn't function at all, it's there more for display and the lock can be pulled out with the key. Maybe that's it...
Unfortunately, unless you can get the piece back in (my glove box lost one of the plastic pieces so I can't fix mine) and no other pieces are missing...you have to get another glove box to use it properly.
